title: Ionized hypocalcemia during out-of-hospital cardiac arrest and cardiopulmonary resuscitation is not due to binding by lactate.
abstract: OBJECTIVE
  To determine the relationship between ionized calcium concentrations and blood lactate levels during cardiac arrest and cardiopulmonary resuscitation (CPR).
  
  
  METHODS
  A prospective cohort study.
  
  
  METHODS
  Emergency department (ED) and general intensive care unit in a city hospital (tertiary care center).
  
  
  METHODS
  32 patients with out-of-hospital cardiac arrest; 14 of the patients had a return of spontaneous circulation (ROSC) and 18 of the patients died.
  
  
  METHODS
  Basic and advanced life support.
  
  
  RESULTS
  Concentrations of ionized and total calcium, bicarbonate, lactate, and pyruvate and pH were simultaneously determined immediately upon arrival at the ED, and at 30 and 60 min. Upon arrival at the ED, all patients had ionized hypocalcemia (1.09 +/- 0.02 mmol/l). Ionized and total calcium concentrations progressively decreased during and after CPR, but pH and bicarbonate concentrations did not show any significant changes. In patients who had ROSC, a significant, but perhaps not clinically relevant, relationship was observed between the ionized calcium concentrations and pH (r2 = 0.152, p = 0.0117). In the patients who died, there were significant correlations between ionized calcium and pH (r2 = 0.382, p = 0.0001) and bicarbonate concentrations (r2 = 0.298, p = 0.0006). No definite correlations were demonstrated when comparing ionized calcium concentrations with lactate and pyruvate concentrations.
  
  
  CONCLUSIONS
  Ionized hypocalcemia during out-of-hospital cardiac arrest and CPR is not due to binding by both lactate and pyruvate, but may be partly due to complexing by bicarbonate, with some modifications due to variations in pH.
authors.affiliation: Department of Anesthesiology and Intensive Care, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Gando
authors.forename: M
authors.initials: M
authors.lastname: Igarashi
authors.forename: T
authors.initials: T
authors.lastname: Kameue
authors.forename: S
authors.initials: S
authors.lastname: Nanzaki
mesh_terms: D000368:Aged; D002118:Calcium / Q000097:blood*; D016887:Cardiopulmonary Resuscitation / Q000009:adverse effects*; D005260:Female; D006323:Heart Arrest / Q000097:blood* / Q000209:etiology; D006801:Humans; D006996:Hypocalcemia / Q000097:blood / Q000150:complications*; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D019344:Lactic Acid; D002118:Calcium